cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

tea6420.c (3364B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2 /*
      3    tea6420 - i2c-driver for the tea6420 by SGS Thomson
      4
      5    Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
      6    Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
      7
      8    The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
      9    4 stereo outputs and gain control for each output.
     10    It is cascadable, i.e. it can be found at the addresses 0x98
     11    and 0x9a on the i2c-bus.
     12
     13    For detailed information download the specifications directly
     14    from SGS Thomson at http://www.st.com
     15
     16  */
     17
     18
     19#include <linux/module.h>
     20#include <linux/ioctl.h>
     21#include <linux/slab.h>
     22#include <linux/i2c.h>
     23#include <media/v4l2-device.h>
     24#include "tea6420.h"
     25
     26MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
     27MODULE_DESCRIPTION("tea6420 driver");
     28MODULE_LICENSE("GPL");
     29
     30static int debug;
     31module_param(debug, int, 0644);
     32
     33MODULE_PARM_DESC(debug, "Debug level (0-1)");
     34
     35
     36/* make a connection between the input 'i' and the output 'o'
     37   with gain 'g' (note: i = 6 means 'mute') */
     38static int tea6420_s_routing(struct v4l2_subdev *sd,
     39			     u32 i, u32 o, u32 config)
     40{
     41	struct i2c_client *client = v4l2_get_subdevdata(sd);
     42	int g = (o >> 4) & 0xf;
     43	u8 byte;
     44	int ret;
     45
     46	o &= 0xf;
     47	v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);
     48
     49	/* check if the parameters are valid */
     50	if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
     51		return -EINVAL;
     52
     53	byte = ((o - 1) << 5);
     54	byte |= (i - 1);
     55
     56	/* to understand this, have a look at the tea6420-specs (p.5) */
     57	switch (g) {
     58	case 0:
     59		byte |= (3 << 3);
     60		break;
     61	case 2:
     62		byte |= (2 << 3);
     63		break;
     64	case 4:
     65		byte |= (1 << 3);
     66		break;
     67	case 6:
     68		break;
     69	}
     70
     71	ret = i2c_smbus_write_byte(client, byte);
     72	if (ret) {
     73		v4l2_dbg(1, debug, sd,
     74			"i2c_smbus_write_byte() failed, ret:%d\n", ret);
     75		return -EIO;
     76	}
     77	return 0;
     78}
     79
     80/* ----------------------------------------------------------------------- */
     81
     82static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
     83	.s_routing = tea6420_s_routing,
     84};
     85
     86static const struct v4l2_subdev_ops tea6420_ops = {
     87	.audio = &tea6420_audio_ops,
     88};
     89
     90static int tea6420_probe(struct i2c_client *client,
     91			  const struct i2c_device_id *id)
     92{
     93	struct v4l2_subdev *sd;
     94	int err, i;
     95
     96	/* let's see whether this adapter can support what we need */
     97	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
     98		return -EIO;
     99
    100	v4l_info(client, "chip found @ 0x%x (%s)\n",
    101			client->addr << 1, client->adapter->name);
    102
    103	sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
    104	if (sd == NULL)
    105		return -ENOMEM;
    106	v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
    107
    108	/* set initial values: set "mute"-input to all outputs at gain 0 */
    109	err = 0;
    110	for (i = 1; i < 5; i++)
    111		err += tea6420_s_routing(sd, 6, i, 0);
    112	if (err) {
    113		v4l_dbg(1, debug, client, "could not initialize tea6420\n");
    114		return -ENODEV;
    115	}
    116	return 0;
    117}
    118
    119static int tea6420_remove(struct i2c_client *client)
    120{
    121	struct v4l2_subdev *sd = i2c_get_clientdata(client);
    122
    123	v4l2_device_unregister_subdev(sd);
    124	return 0;
    125}
    126
    127static const struct i2c_device_id tea6420_id[] = {
    128	{ "tea6420", 0 },
    129	{ }
    130};
    131MODULE_DEVICE_TABLE(i2c, tea6420_id);
    132
    133static struct i2c_driver tea6420_driver = {
    134	.driver = {
    135		.name	= "tea6420",
    136	},
    137	.probe		= tea6420_probe,
    138	.remove		= tea6420_remove,
    139	.id_table	= tea6420_id,
    140};
    141
    142module_i2c_driver(tea6420_driver);